1. Use ANS to chain calculations
After any calculation, press 2nd + (−) to insert ANS — the last result. Instead of typing 3.14159 again, just use ANS × 2 + 5. This prevents rounding errors from manual re-entry.
2. Recall the last expression with 2nd + ENTER
Pressed ENTER too soon? Hit 2nd + ENTER to pull the previous expression back to the screen. Edit it with the arrow keys. This saves you from retyping long expressions.
3. Switch angle mode before trig problems
Press MODE and check whether DEGREE or RADIAN is highlighted. AP Calculus uses radians; most geometry and precalculus uses degrees. Getting the wrong answer on a test because of mode is one of the most avoidable errors.
4. Store values in variables
After calculating a result, press STO→ then a letter (A through Z) to store it. Later, press ALPHA + that letter to recall it. Useful when the same intermediate value appears in multiple formulas.
5. Use the MATH menu for abs, round, and roots
Press MATH to access abs( (absolute value), ³√( (cube root), round( (rounds to N places), and more. These functions don't appear on the main keyboard — students who don't know the menu waste time doing them by hand.
6. Calculate nCr and nPr directly
For combinations and permutations: type the n value, press MATH → PRB → nCr (or nPr), then type r. Example: 10 nCr 3 = 120. No formula sheet needed.
7. Use 1-Var Stats to check statistics problems
Enter your data into L1 (press STAT → Edit → L1). Then press STAT → CALC → 1-Var Stats. The calculator shows mean, sum, standard deviation, min, Q1, median, Q3, and max. Cross-check your hand calculations instantly.
8. Graph to find zeros and intersections visually
Enter functions in Y= and press GRAPH. Press 2nd + CALC → zero to find where a function crosses the x-axis. Press 2nd + CALC → intersect to find where two functions meet. Much faster than solving algebraically in a test setting.
9. Use the TABLE feature to spot function behavior
Press 2nd + GRAPH (TABLE) to see a table of x/y values for any graphed function. Set TblStart and ΔTbl in 2nd + WINDOW (TBLSET). Useful for spotting zeros, finding patterns, and building intuition before solving.
10. Compute definite integrals numerically
Press MATH → fnInt( and enter fnInt(expression, X, lower, upper). Example: fnInt(X²,X,0,3) = 9. The TI-84 approximates the integral numerically — close enough for checking answers on most AP and college exams.
11. Clear RAM before a test
If your teacher requires a cleared calculator: press 2nd → MEM → Reset → All Memory → Reset. This wipes programs, variables, and lists. If you only need to clear variables: 2nd → MEM → Reset → Defaults → Reset.
12. Change decimal display with MODE
Press MODE and move to the Float row. Change Float to a fixed number (like 4) to always show 4 decimal places. Change back to Float for general use. Helps when a problem specifies "round to 2 decimal places."